package com.sinacom.ibuilding.util;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class CharacterEncodingFilter implements Filter {
	/**
	 * 16 The default character encoding to set for requests that pass through
	 * 17 this filter. 18
	 */

	protected String encoding = null;

	/**
	 * 22 The filter configuration object we are associated with. If this value
	 * 23 is null, this filter instance is not currently configured. 24
	 */
	protected FilterConfig filterConfig = null;

	protected boolean ignore = true;

	public void destroy() {
		this.encoding = null;
		this.filterConfig = null;
	}

	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		// Conditionally select and set the character encoding to be used
		if (ignore || (request.getCharacterEncoding() == null)) {

			String encoding = selectEncoding(request);

			if (encoding != null)

				request.setCharacterEncoding(encoding);
		}

		chain.doFilter(request, response);

	}

	public void init(FilterConfig filterConfig) throws ServletException {
		this.filterConfig = filterConfig;

		this.encoding = filterConfig.getInitParameter("encoding");

		String value = filterConfig.getInitParameter("ignore");

		if (value == null)

			this.ignore = true;

		else if (value.equalsIgnoreCase("true"))

			this.ignore = true;

		else if (value.equalsIgnoreCase("yes"))

			this.ignore = true;

		else

			this.ignore = false;

	}

	protected String selectEncoding(ServletRequest request) {

		return (this.encoding);

	}

}
